Control circuit for motor driven file



s. K. HANDEL 3,059,984 CONTROL CIRCUIT FOR MOTOR DRIVEN FILE Oct. 23,' 1962 2 Sheets-Sheet 1 Filed March 15, 1961 ATTORIIEYS- 3,059,984 CONTROL CIRCUIT FOR MOTOR DRIVEN FILE Filed March 15, 1961 S. K. HANDEL Oct. 23, 1962 2 Sheets-Sheet 2 A T TOIQNEYS.

United States Patent Ofiice 3,059,984 Patented Oct. 23, 1962 3,059,984 CONTROL CIRCUIT FOR MOTOR DRIVEN FILE Siegfried K. Handel, Hamilton, Ohio, assignor to The Mosler Safe Company, Hamilton, Ohio, a corporation of New York Filed Mar. 15, 1961, Ser. No. 95,956 Claims. (Cl. 312-223) This invention relates to filing devices and is particularly directed to a motor drive and associated control circuit for automatically shifting pans or other receptacles in a rotary file to bring a selected group of cards, or the like, to an accessible position.

At the present time, there is a rapidly increasing use of motorized filing equipment, particularly rotary files, in which horizontal card containing trays are shifted in an arcuate path within a housing. Motor driven rotary files are highly advantageous for several reasons. One of the most significant of these reasons is that a file can store a tremendous number of cards in only a small fraction of the space required to store the same amount of cards in a conventional drawer file. In the second place, a motorized file provides ready access to the stored material. When using such a file, the operator remains seated before a conventional work or posting table and manipulates suitable controls, such as push buttons, to cause the selected cards to be presented at an accms opening in the file housing.

In the past, many different rotary file constructions have been proposed. While the details of construction of these files do not constitute a part of the present invention, it is considered that an understanding of the general construction of a rotary file will be helpful to a proper understanding of the significance of the present invention.

In general, rotary files are of either of one of two types. The first type is referred to as the elevator type file, while the second type is referred to as the drum type file. In an elevator file a plurality of horizontally disposed spaced pans are mounted upon suitable carriers for arcuate movement within the file housing. These carriers, of which many types are known in the prior art, are effective to shift the trays successively into registry with an opening in the file housing adjacent to the posting table Where they are readily accessible to the operator. The carriers in a conventional file are power driven by a reversible motor and some type of switch arrangement is provided adjacent to the operator station for controlling operation of the motor to bring the desired pan into registry with the cabinet opening.

A drum file is of somewhat difierent construction. Specifically, a drum file includes one or more rotatable drum members having peripheral card receiving pockets. The drums are driven through a suitable motor drive and as in the elevator file a control switch is positioned adjacent to the operator for controlling operation of the drive to bring the desired card receiving pocket into registry with an access opening in the file cabinet. It is to be understood that the present control circuit can be used equally as well with a drum type file as with an elevator type file, although for purposes of brevity only an installation in an elevator file will be described in detail.

One of the difficulties with previously proposed rotary files has been that these files have used DC. motors. These DC. motors together with the large relays and rectifiers they require have occupied an excessively large amount of space. Thus, these elements have detracted to some extent from one of the primary advantages of a rotary file, i.eL, its compactness for handling a given amount of record material.

One of the principal objects of the present invention is to provide a rotary file in which an A.C. motor is used to drive the carrier members. The use of such a motor provides many advantages of particular importance in a rotary file. Thus, the A.C. motor facilitates a reduction in the overall size of the file unit due to the fact that the need for a rectifier is eliminated and small A.C. plug-in type relays can be used in place of the large heavy load 11C. relays previously required. The use of an A.C. motor is also advantageous since it eliminates arcing of the type present in a brush-type motor and thus eliminates the need for constant maintenance of the unit.

A further object of the present invention is to pro vide a file in which an A.C. motor is initially used to drive the carrier for shifting the card carrying pans, or the like, at a relatively high rate of speed and is subsequently dynamically braked to almost instantaneously stop the pans at the desired position. Moreover, in the present file the motor is instantly reversible and means are provided for automatically energizing the motor to rotate in the direction to shift the selected card tray through the shortest possible distance to reach its accessible position.

Consequently, one of the principal advantages of the present motor driving control system is that it makes it possible to gain access to any of a large number of cards (200,000 in a typical file) in less than three seconds. Moreover, the desired cards are always stopped at precisely the point at which they are most convenient to the operator. Since the motor is dynamically braked, there is no coasting of the file trays past the desired position.

Another object of the present invention is to provide a motor control circuit including a reversing relay having contacts for conditioning the motor power circuit to energize the motor so that it is rotated in the desired direction in combination with a separate power relay having contacts efiective to complete the motor energization circuit. In accordance with the present invention, the reversing relay contacts are always closed in accordance with the desired direction of motor rotation before the power relay contacts are closed. This is highly advantageous since it eliminates arcing on the power relay contacts.

More particularly, the present invention is predicated in part upon the concept of providing a rotary file including a reversible A.C. motor and a motor control circuit comprising three relays, a braking relay, a reversing relay and a power relay. Two conductive paths are provided to the power and braking relays. The reversing relay includes a lock-out contact disposed in each of these paths. This contact is in addition to two reversing contacts in series with contacts of the power relay in the main motor energization circuit. The relay lock-out contact is a two position contact and is connected so that when the desired direction of motor rotation is such that the reversing relay is not energized, current is applied immediately to the power and brake relays. However, when the motor is to be operated in the reverse direction in which the reversing relay is energized to shift the reversing contacts, a circuit is not completed to the power and brake relays until after the reversing relay is energized to close its lockout contact. The motor reversing relay thus performs a double function in that it not only conditions the motor energization circuit to control the direction of rotation of the motor, but also it positively prevents plugging of the motor without the need for any latching relays orthe like.

Another advantage of the present control system is that it provides for either manual or automatic operation according to the operators desires. More particularly, the present control system comprises one set of key operating switches in which each switch corresponds to one pan of the file. Thus, if the operator wishes to obtain access to pan No. 1, she merely depresses the key corresponding to pan No. 1 and the file is automatically driven to bring pan No. 1 into registry with the access opening adjacent to the posting table. On the other hand, the operator may depress either of two other keys to cause the pans to be driven in the selected direction until the desired pan is positioned at the access opening. The operator then releases the key causing the drive motor to be deenergized and dynamically braked so that it is brought to almost an instantaneous stop.

One of the objectives of the present invention is to provide a positive electrical interlock between the manual switches and the switches utilized for automatic operation. According to the present invention, this automatic interlock is provided by interconnecting the two manual switches in series with each other and with the remaining selector switches. When one of the two manual opera tion switches is closed, a circuit is open to the selector switches so that the depression of one or even all of these latter switches would have no effect upon the operation of the unit.

These and other objects and advantages of the present invention will be more readily apparent from the following detailed description of the drawings illustrating a preferred embodiment of the invention.

In the drawings:

FIGURE 1 is a perspective view showing one preferred form of elevator file unit embodying the control circuit of the present invention.

FIGURE 2 is a schematic circuit diagram of a control circuit embodying the principles of the present invention.

The overall construction of one typical form of elevator file in which the present control system is particularly adapted for use is shown in FIGURE 1. As there shown, the file unit comprises a housing 11 having a front opening 12 adapted to provide access to a series of horizontal rows of pans 13, each of which carries a plurality of individual card receiving trays. These pans are mounted for movement within the housing to a position in alignment with opening 12 and to other positions in which the trays are disposed remote from the opening. The number of pans provided in the file varies in accordance with the desired capacity of the unit. By way of example, some files may have as few as nine pans, while other units may have as many as twenty. In any case, however, the trays are equally spaced along the carrier member. In the specific file shown there are thirteen pans provided.

In practice, the ends of pans 13 are mounted upon suitable carrier members, such as spaced pairs of chains, wheels or the like. The pans are also connected to a suitable stabilizing mechanism (not shown) which is effective to maintain the pans and trays in an upright position as they move along the path defined by the carriers. It is to be understood that the exact construction of the pans, carriers, and their associated stabilizing mechanism constitute no part of the present invention. Those skilled in the art are familiar with many different suitable pan, carrier and stabilizing mechanism conjs tructions with which the present motor control circuit can be advantageously used.

Additionally, it is to be understood that the present control circuit could be used if desired with single or multiple drum file units, such as those shown in Knittel Patents Nos. 2,148,357 and 2,796,308. In general, a drum file includes a plurality of pockets and compartments equally spaced about its periphery and adapted to receive and store groups of record cards. These drums are mounted for rotation on a horizontal axis and when utilized in conjunction with the present motor control circuit are driven by a reversible motor in the same manner as the elevator file described in detail below.

The elevator file 10 shown in FIGURE 1 further cornprises a posting table 14 extending forwardly of the file housing adjacent to the area where the pan containing selected card trays are stopped. An auxiliary table 15 also extends forwardly of the housing adjacent one side thereof. A set of selector keys 16 is mounted in a recessed well provided at the center of the posting table. As is explained in detail below, the set of keys 16 includes one key associated with each horizontal pan together with an up key, a down key and a reset key. By pressing the key corresponding to the desired pan, an operator sitting in front of the file unit can cause any desired pan to be brought into alignment with the opening adjacent to posting table 14.

A master switch 17 is mounted at the front of the housing above auxiliary tabe 15. The front opening 12 of the housing is adapted to be closed by a roll top member 18. The housing is further provided with a panel 20 for providing access to the motor and control circuit and other access panels 21 and 22 for providing access to the interior of the main portion of the housing. A safety bar 19 extends across the front portion of the housing between the inner edge of posting table :14 and the pans 13. As is explained below, the safety bar 19, roll top 1-8 and access panels 20, 21 and 22 each have associated therewith suitable safety switches for preventing motor operation under unsafe conditions. It is to be understood that this brief description of the file housing is provided by way of example only so as to provide a full understanding of one complete embodiment of a file with which the present motor control circuit can be used advantageously. However, the details of construction of the housing and its components, such as the safety bar, roll top and the like, constitute no part of the present invention which is concerned solely with the drive motor control system.

As is best shown in FIGURE 2, file 10 further includes a reversible electric motor 23 which is mechanically interconnected to the carrier members (not shown) in any suitable manner, as for example through a gear reduction unit and chain and sprocket drive. Motor 23 is a self-braking induction motor. The application of power to the motor, the direction of rotation of the motor and the application of braking current to the motor are respectively controlled by power relay 24, reversing relay 25 and brake relay 26.

The energization of these relays is in turn controlled through a circuit including rectifiers 27, 28 and 30 and a selector switch 31 including a rotating plate which is mechanically interconnected to the carrier drive for synchronous movement with file pans 13. The control circuit for motor 23 also comprises selector buttons 16 and a safety circuit 32. Low voltage for energizing the safety circuit and control circuit is obtained through a transformer 33 having a primary winding connected across power lines 34 and 35.

More specifically, transformer 33 includes a primary winding 36 which is connected to power line 34 and to power line 35 through a conventional circuit breaker 3'7 and master switch 17. Transformer 33 includes a secondary winding 38 which is effective to produce a control voltage which in the preferred embodiment is ap proximately 25 volts. Pilot lights 40 are connected across the output terminals of secondary winding 38.

A lead 41 is connected to one terminal of the secondary winding 38 and is in turn connected to a coil 42 of safety relay 43. Safety relay 43 includes a first contact 44 in series with relay coil 42. When coil 42 is energized, contact 44 is shifted to the position shown in dotted lines in FIGURE 2 where it completes a cir cuit to lead 45 of the safety circuit 32. Lead 45 is connected to a safety cable switch 39 associated with a safety bar 32. This safety cable switch 39 is in turn joined to a mercury switch 46 associated with the posting table, the mercury switch being opened whenever the posting table is raised or closed.

Mercury switch 46 is connected in series with access panel switches 47 and 48, these switches being opened when access panels 21 and 22 are open. Access switches 47 and 48 are in turn connected in series with a motor access panel switch 50. This latter switch is open whenever panel 20 is open. Switch 50 is joined in series with a manual operating limit switch 51. This switch is open whenever motor 23 is cranked by hand, as for example during a power failure. The switch thus prevents automatic operation of the motor in the event that power is restored.

The final switch in line 45 of the safety circuit is a roll top limit switch 52. This latter switch is connected so that it is closed only when roll top 18 is completely retracted to its open position shown in FIGURE 1. The opposite end of lead 45 is returned to the opposite terminal of secondary winding 38.

One line of the switch and relay portion 53 of the control circuit is taken from one terminal of secondary winding 38 through lead 45. Thus line 54 is connected to a reset and stop switch 55. This switch is a single pole double throw switch having a normally open contact joined through lead 56 to a normally closed contact 44 of the safety relay. A normally closed contact of reset switch 55 is connected to a second contact 57 of safety relay 43. This contact is in turn connected through lead 58 to the movable contact of up switch 60. The up switch 60 is the first switch of the set of key operated switches 16. Each of the switches in this set is a double throw single pole relay. The contacts of these switches in their normally closed position are connected in series.

More particularly, up switch 60 is connected in series with down switch 61. The down switch is in turn connected in series with key operated selector switches K1, K2, K3, K4, K5, K6, K7, K8, K9, K10, K11, K12 and K13. A conventional spring loaded latching bar is provided for key switches K1-K13 so that once a key has been depressed the switch remains closed until another key is provided. Each of the key operated switches K1- K13 corresponds to one of the thirteen pans in the file unit. It will, of course, be appreciated that if a lesser or greater number of pans is provided in the file unit, a correspondingly greater or lesser number of key switches will be provided. Each of the normally open contacts of the key switches Kl-K13 is respectively connected to a corresponding stationary contact 81-813 of selector switch 31. The details of construction of one preferred form of selector switch are shown in my copending application entitled Selector Switch For Rotary Files, Serial No. 862,551, filed December 29, 1959.

In essence, selector switch 31 comprises a stationary contact carrying plate for supporting stationary contacts S1-S13. These contacts are equally spaced about the periphery of a circle. Additionally, the switch comprises a rotary switch plate 62 having two conductive sectors 63 and 64 of generally semi-circular configuration. These conductor sectors are completely insulated from one another. In addition to stationary contacts S1613, switch 31 comprises two stationary commutator contacts 65 and 66. These latter contacts are in respective engagement with a commutator ring 67 in electrical connection with sector 63 and a commutator ring 68 in electrical connection with sector 64.

Contact 65 is joined to a lead 70, the opposite end of which is joined to a normally open contact of up switch 60. In a similar manner, contact 66 is joined to a lead 71, the opposite end of which is connected to the normally open contact of down switch 61. A conductor 72 is joined to lead 70. This conductor is connected to one input of a rectifier bridge 30. A second input lead 73 of this bridge is taken from a terminal of secondary winding 38 of transformer 33. The output leads of bridge 30 are connected across coil 74 of direction relay 25. Lead 72 is also connected to the normally open or lock-out contact, 75 of direction relay 25. This contact is in turn adapted to be joined through its associated relay contact arm to rectifier bridges 27 and 28.

The second input leads to these rectifier bridges are joined to the secondary winding of transformer 38 in the same manner as the input lead of bridge 30. The output leads of rectifier bridge 27 are connected across relay coil 76 of power relay 24.

Similarly, the output leads of rectifier bridge 28 are connected across coil 77 of braking relay 26. A series connected resistance 78 and capacitor 80 are connected in parallel with this coil function as a time delay element so that the coil remains energized for a predetermined length of time, in the preferred embodiment about 300 milliseconds, after the circuit to relay 28 is opened. The power, braking and direction relays have contacts in the main motor power circuit indicated generally at 81. These contacts are effective to control the starting, stopping and direction of rotation of the armature of motor 23.

Motor 23 is a capacitor start induction motor comprising a rotor 82 of standard build-up squirrel cage construction. Motor 23 also includes a main winding 83 and a dynamic brake winding 84 having an exitation phase 85 and a short-circuited phase 86. Additionally, the motor includes a phase winding 87. The details of construction of one suitable motor of the type are shown in Noodleman Patent No. 2,626,059. Additionally, there is associated with motor 23 an emergency brake winding 88 which is effective when deenergized to actuate a magnetic disc type or other suitable form of brake.

Power for energizing motor 23 is taken from power lines 34 and through lines 90 and 91 respectively. One terminal of main winding 83 is connected to a lead 92. This lead is adapted to be joined to conductor 91 through relay contacts 93 and 94 of motor reversing relay 25 and power relay 24 respectively. The same terminal of main winding 83 is adapted to be joined to lead 98 through lead 95 and contacts 96 and 97 of motor reversing relay 25 and power relay 24.

The opposite lead of main winding 83 is connected in series with the coil 98 of a motor start relay. This coil is in turn connected to relay contact set 93. The coil 98 of the motor start relay has connected in parallel with it a resistor 99 and inductance 100. The motor start relay coil 98 is also connected to a lead 1101 which is joined to a stationary contact associated with the relay contact set 96.

One lead of phase winding 87 is connected through a conductor 102 to relay contact 97. A second lead of winding 87 is joined through a conductor 103, relay contacts 104 of the motor start relay and capacitor 105 to relay contact 94 of the power relay. Dynamic brake winding 85 is connected to a normally closed stationary contact of power relay 94 and is connected to ganged contacts 106 of brake relay 26. The stationary contacts of this set are tied together and are joined to a stationary terminal of power relay contact 97. The emergency brake winding 88 is similarly connected across a stationary contact of power relay 97 and a contact 107 of safety relay 43. A connection is completed through contact 107 to power line 91.

In normal use cards, for example alphabetically arranged customer cards, are placed within the trays in the various pans. Thus, the trays in pan 1 might contain all of the cards beginning with the letters A and B. Pan 2 might support all of the cards beginning with the letters C and D, and so forth. A file of the type shown in FIGURE 1 has a capacity to house two hundred thousand 3" X 5" cards. The operator is seated in front of posting table 15 directly in front of the recessed well containing selector keys 16.

The operator first closes master switch 17 and then presses reset push button on the keyboard to close reset contacts 55. This completes a circuit through safety relay 43 closing contacts 44 and 57 of this relay. Twentyfive volt A.C. power is then applied to the safety circuit 32 and to the switch and relay portion of the control circuit.

The operator can select any desired tray either automatically by depressing one of the selector buttons associated with the desired tray, or manually by actuating either the up or down push buttons which complete a circuit bypassing the selector switch.

As was explained previously, each of the keyboard contacts Kl-K13 is associated with one pan of the file and is electrically connected to one of the contacts 51-513 of selector switch 31. The selector switch, when energized, by one of the contacts, automatically selects the direction in which motor 23 is driven through the shortest distance to bring the desired pan into position in opening 12.

By way of example, suppose that the last previous card selectieon has been made so that pan No. 7 is aligned in opening 12 at posting table 14. Assume that the operator desires to gain access to the cards carried by pan No. 10. To do so, push button K110 is closed to complete a circuit to stationary contact S of the selector switch. The operator immediately releases this switch key but it is held closed by the latching mechanism (not shown) referred to above. It is to be noted at this point that the key operated switches Iii-K13 and the up and down switches are electrically interlocked to prevent simultaneous operation of two or more switches. Specifically, each of these switches is provided with two contacts, a normally open contact and a normally closed contact. The normally closed contacts of the switches are connected in series and this series connection is broken whenever a switch is closed to provide a circuit to the selector switch. Thus, if before switch K10 is closed, the up switch 60' should also be closed, closing of switch Kit? will have no effect since the circuit to switch Klltl is open at the up switch.

Returning to the example of operation, when switch Kw is closed to energize contact Sllfi, that contact is in engagement with the right-hand conductive segment of the rotary disc of the selector switch. Thus, an electrical circuit is established from the stationary contact Slit to commutator contact 66. Power is thus applied from this connection through closed contact '75 of motor reversing relay to rectifier bridges 2'7 and 28. These bridges in turn cause the energization of power relay 24L and braking relay 26. When power relay 24 is closed, its contacts 94 and 97 close to supply power to the motor which will rotate clockwise. Brake relay contact 1% closes simultaneously, but the circuit to dynamic brake winding 85 is opened at power relay contact W7.

The armature of motor 23 is thus eifective to drive the carriers to shift pans 13 toward its desired position. Since the selector switch disc is driven synchronously with the motor and carriers, this disc also rotates clockwise until the radial insulating strip between the two conductive halves of the rotary disc is in registry with contact Slit. When this occurs, a pan No. 10 is properly positioned and the electrical circuit is opened to rectifiers 27 and 28 causing de-energization of power relay coil 76. Contacts 94 and 97 of the power relay open immediately to de-energize the main winding of motor 2.3 and to supply power to brake winding 84 of the motor. This winding dynamically brakes the motor so that the file carrier stops in a minimum amount of time, with the desired pan accurately positioned adjacent to table 14. It is to be understood that contact 106 of the brake relay is held closed until the motor reaches zero speed. This requires slightly less than 300 milliseconds. Brake relay 26 is held energized during this required period by the combination of resistor '78 and capacitor 80, which capacitor charges when energized and discharges into the relay coil when de-energized.

After the operator has finished with the cards carried by the pans in tray 10, assume that it is desired to gain access to pan No. 7 again. This is accomplished by depressing key K7 which energizes contact S7 of the selector switch. This contact is now in engagement with the lefthand segment of the rotary disc of the switch so that a circuit is completed from contact S7 through the conductive disc to commutator contact 65. This commutator contact in turn completes a circuit to rectifier bridge 30 causing energization of the motor reversing relay coil 74. It is to be noted that at this time that the braking relay 26 and power relay 24 remain deenergized because lock-out contact 75 of the motor reversing relay remains open. When reversing relay 25 is energized, it is effective to cause closing of contacts 93 and 96 to reverse the connections to main winding 83 of the drive motor 23. At the same time, contact 75 of the motor reversing relay is closed to complete a circuit to the brake and power relays 77 and 76. The contacts 94, 97 and 106 of the braking and power relays then close after reversing contacts 93 and are closed. Energy is thus applied to the motor winding to cause the motor armature to be driven in the opposite direction from its previous direction of rotation, i.e., counterclockwise in FIGURE 2. The motor continues to operate until the insulating segment between the discs is in registry with contact S7 of the selector switch. This causes the motor reversing and power relays to become deenergized immediately and the braking relay to become de-energized approximately 360 milliseconds later. The motor rotor is dynamically braked to stop in the same manner as explained above. This control system makes it possible for the operator to automatically gain access to any of the two hundred thousand cards in the file within less than three seconds.

If for any reason the operator would prefer to control the rotation manually by means of up or down switches 60 or 61, these switches are depressed instead of the selector switches Til-K13. Down switch 61 is effective to complete a circuit only to braking relay 26 and power relay 24 to cause clockwise rotation of the motor, while up switch energizes reversing relay 25 together with brake relay 26 and power relay 24 to cause operation of the motor in the opposite or counterclockwise direction. In either case, the circuits completed by the up and down switch completely bypass the selector switch to bring the selected pan into position. When using the up and down switches, the operator depresses either the up or down switch and holds that switch closed until the desired pan appears in opening 12. The operator then releases the switch to deenergize the power and motor reversing relay (if energized). Opening of the up or down switch also causes the braking relay 26 to be deenergized after approximately 300 milliseconds during which the motor is dynamically braked to a stop in the manner previously explained.

One further advantage of the present control system is that if the operator makes a mistake, for example presses key 7 when she really means to press key Ill, the error can be rectified without waiting for the file pans to be posi tioned and brought to a stop. This is true even if the new pan position requires a reversal of direction of rotation of the motor. Specifically, all that is required is that the operator depress the new, or correct, key. Thi will compete a new circuit through the selector switch to the power, braking and reversing relays. If the new key requires that the motor operate in the other direction, the reversing relay can be either changed from a deeenergized to an energized position or vice versa. In either case, the main reversing contacts in series with the main power relay contacts are actuated at the same time that lock-out contact 75 is actuated. Thus, the leads of main winding of the motor are reversed and power is immediately reapplied to the motor. Since the motor is instantly reversible, the motor armature changes direction of rotation to drive the pans in the opposite direction.

Having described my invention, I claim:

1. A drive system for a rotary file of the type including 9' a housing having an access opening, a plurality of card carrying receptacles, means mounting said receptacles for movement within the housing relative to the access opening, said drive system comprising an alternating current, induction motor having a main winding and a dynamic braking winding, a control circuit for controlling the direction of operation of said motor and the dynamic braking thereof, said control circuit comprising a brake relay, a reversing relay and a power relay, circuit means including a plurality of selectively operable switches for energizing said relays, said circuit means including mean for energizing said reversing relay before the energization of said power relay.

2. A drive system for a rotary file of the type including'a housing having an access opening, a plurality of card carrying receptacles, means mounting said receptacles for movement within the housing relative to the access opening, said drive system comprising an alternating current, induction motor having a main winding and a dynamic braking winding, a control circuit for controlling the direction of operation of said motor and the dynamic braking thereof, said control circuit comprising a brake relay, a reversing relay and a power relay, each of said relays including a coil, said reversing relay and said power relay having contacts in series with said main winding, circuit means including a plurality of selector switches for energizing said relay coils, said circuit means including a contact of said reversing relay in the energization circuit of said power relay coil whereby said reversing relay contacts in series with the power relay contacts are closed in accordance with the state of energization of said reversing relay before said power relay contacts are closed.

3. A drive system for a rotary file of the type including a housing having an access opening, a plurality of card carrying receptacles, means mounting said receptacles for movement within the housing relative to the access opening, said drive system comprising an alternating current, induction motor having a main winding and a dynamic braking winding, a control circuit for controlling the direction of operation of said motor and the dynamic braking thereof, said control circuit comprising a brake relay, a reversing relay and a power relay, each of said relays including a coil, said brake relay having contacts in series with said dynamic braking coil, rectifier means for applying a DC. potential to said brake coil, means for deenergizing said rectifier means and said power relay when the selected receptacle is in registry with said access opening, saidbrake relay having time delay means in circuit connection therewith, where-by said brake relay remains energized for a predetermined time sufiicient for said motor to be dynamically braked to a stop.

4. A drive system for a rotary file of the type including a housing having an access opening, a plurality of card carrying receptacles, means mounting said receptacles for movement within the housing relative to the access opening, said drive system comprising an alternating current, induction motor having a main winding and a dynamic braking winding, a control circuit for controlling the direction of operation of said motor and the dynamic braking thereof, said control circuit comprising a brake relay, a reversing relay and a power relay, each of said relays including a coil, circuit means for energizing said coils to cause energization of said main motor winding and subsequent energization of said dynamic braking coil, said circuit means comprising two manual operation switches being effective to cause rotation of said motor in opposite directions, and a plurality of selector switches, each of said switches being associated with one of said receptacles, said manual operation switches normally being in series connection with said selector switches, whereby when one of said manual operation switches is closed a circuit to said selector switches is open.

5. A drive system for a rotary file of the type including a housing having an access opening, a plurality of card carrying receptacles, means mounting said receptacles for movement within the housing relative to the access opening, said drive system comprising an alternating current, induction motor having a main winding and a dynamic braking winding, a control circuit for controlling the direction of operation of said motor and the dynamic braking thereof, said control circuit comprising a brake relay, a reversing relay and a power relay, each of said relays including a coil, a rectifier connected to each of said coils, circuit means including a plurality of selectively operable switches for energizing said rectifiers, a rotary selector switch having stationary contacts respectivly connected to each of said switches, a rotary disc member having two conductor portions insulated from one another, two commutator contacts in respective electrical connection with each of said conductive portions, one of said commutator contacts being connected directly to the rectifier associated with said reversing relay and being connected to the rectifiers associated with said braking and power relays through a normally open contact of said braking relay, the other of said commutator contacts being connected to the rectifiers joined to said brake relay and power relay through a normally closed contact of said brake relay.

6. A drive system for a rotary file of the type including a housing having an access opening, a plurality of card carrying receptacles, means mounting said receptacles for movement within the housing relative to the access opening, said drive system comprising an alternating current, induction motor having a main winding and a dynamic braking winding, a control circuit for controlling the direction of operation of said motor and the dynamic braking thereof, said control circuit comprising a brake relay, a reversing relay and a power relay, each of said relays including a coil, a rectifier connected to each of said coils, circuit means including a plurality of selectively operable switches for energizing said rectifiers, a rotary selector switch having stationary contacts respectively connected to each of said switches, a rotary disc member having two conductor portions insulated from one another, two commutator contacts in respective electrical connection with each of said conductive portions, one of said commutator contacts being directly connected to the rectifier associated with said reversing relay and being connected to the rectifiers associated with said braking and power relays through a normally open contact of said braking relay, the other of said commutator contacts being connected to the rectifiers joined to said brake relay and power relay through a normally closed contact of said brake relay, and an R-C circuit connected across said brake relay for holding said relay energized after the deenergization of said power relay.

7. A drive system for a rotary file of the type including a housing having an access opening, a plurality of card carrying receptacles, means mounting said receptacles for movement within the housing relative to the access opening, said drive system comprising an alternating current, induction motor having a main winding and a dynamic braking winding, a control circuit for controlling the direction of operation of said motor and the dynamic braking thereof, said control circuit comprising a brake relay, a reversing relay and a power relay, each of said relays including a coil, said brake relay having normally open contacts in series with normally closed contacts of said power relay, circuit means including a plurality of selector switches for energizing said relay coils, and means for maintaining said brake relay energized for a short time following deenergization of said power relay.

8. A drive system for a rotary file of the type including a housing having an access opening, a plurality of card carrying receptacles, means mounting said receptacles for movement within the housing relative to the access opening, said drive system comprising an alternating current, induction motor having a main Winding and a dynamic braking winding, a control circuit for controlling the 11' direction of operation of said motor and the dynamic braking thereof, said control circuit comprising a brake relay, a reversing relay and a power relay, each of said relays including a coil, said brake relay having normally open contacts in series with normally closed contacts of said power relay, circuit means including a plurality of selector switches for energizing said relay coils, and means for maintaining said brake relay energized for a short time following deenergization of said power relay, said last named means comprising a rectifier connected in the energization circuit of said brake relay coil, and RC circuit means connected across said brake relay coil.

9. A drive system for a rotary file of the type including a housing having an access opening, a plurality of card carrying receptacles, means mounting said receptacles for movement within the housing relative to the access opening, said drive system comprising an alternating current, induction motor having a main winding and a dynamic braking winding, a control circuit for controlling the direction of operation of said motor and the dynamic braking thereof, said control circuit comprising a brake relay, a reversing relay and a power relay, each of said relays including a coil, said brake relay having normally open contacts in series with normally closed contacts of said power relay, said reversing relay and said power relay having contacts in series with said main winding, circuit means including a plurality of selector switches for energizing said relay coils, said circuit means including a contact of said reversing relay in the energization circuit of said power relay coil whereby said reversing relay contacts in series with the power relay contacts are closed in accordance with the state of energization of said reversing relay before said power relay contacts are closed.

10. A drive system for a rotary file of the type including a housing having an access opening, a plurality of card carrying receptacles, means mounting said receptacle for movement within the housing relative to the access opening, said drive system comprising an alternating current, induction motor having a main winding and a dynamic braking winding, a control circuit for controlling the direction of operation of said motor and the dynamic braking thereof, said control circuit comprising a brake relay, a reversing relay and a power relay, each of said relays including a coil, said brake relay having normally open contacts in series with normally closed contacts of said power relay, said reversing relay and said power relay having contacts in series with said main winding, circuit means including a plurality of selector switches for energizing said relay coils, said cuit means including a contact of said reversing relay in the energization circuit of said power relay coil whereby said reversing relay contacts in series with the power relay contacts are closed in accordance with the state of energization of said reversing relay before said power relay contacts are closed, and means for maintaining said brake relay energized for a short time following deenergization of said power relay.

11. A drive system for a rotary file of the type including a housing having an access opening, a plurality of card carrying receptacles, means mounting said receptacles for movement within the housing relative to the access open, said drive system comprising an alternating current, induction motor having a main winding and a dynamic braking winding, a control circuit for controlling the direction of operation of said motor and the dynamic braking thereof, said control circuit comprising a brake relay, a reversing relay and a power relay, each of said relays including a coil, said brake relay having normally open contacts in" series with normally closed contacts of said power relay, said reversing relay and said power relay having contacts in series with said main winding, circuit means including a plurality of selector switches for energizing said relay coils, said circuit means including a Contact of said reversing relay in the energization circuit of said power relay coil whereby said reversing relay contacts in series with the power relay contacts are closed in accordance with the state of energization of said reversing relay before said power relay contacts are closed, and means for maintaining said brake relay energized for a short time following deenergization of said power relay, said last named means comprising a rectifier connected in the energization circuit of said brake relay coil, and R-C circuit means connected across said brake relay coil.

12. A drive system for a rotary file of the type in cluding a housing having an access opening, a plurality of card carrying receptacles, means mounting said receptacles for movement within the housing relative to the access opening, said drive system comprising an alternating current, induction motor having a main winding and a dynamic braking winding, a control circuit for controlling the direction of operation of said motor and the dynamic braking thereof, said control circuit comprising a brake relay, a reversing relay and a power relay, each of said relays including a coil, circuit means for energizing said coils to cause energization of said main motor winding and subsequent energization of said dynamic braking coil, said circuit means comprising first and second manual operation switches for causing rotation of said motor in opposite directions, and a plurality of selector switches, each of said selector switches being associated with one of said receptacles, a rotary switch having stationary contacts in respective connection with said selector switches, a rotary disc having two conductive sectors and two commutators in engagement with said sectors, a first circuit interconnecting one of said commutator contacts with said reversing relay coil and with said brake relay coil and power relay coil through a normally open contact of said reversing relay, and a second circuit interconnecting the other of said cornmutator contacts to the power relay coil and brake relay coil through a normally closed contact of said brake relay, means interconnecting said first manual switch to said first circuit and means interconnecting said second manual switch to said second circuit.

13. A drive system for a rotary tfile of the type including a housing having an access opening, a plurality of card carrying receptacles, means mounting said receptacles for movement within the housing relative to the access opening, said drive system comprising an alternating current, induction motor having a main winding, an excitation phase brake winding, and a short circuit brake winding, a control circuit for controlling the direction of operation of said motor and the dynamic braking thereof, said control circuit comprising a brake relay having contacts in circuit with said excitation phase winding, a reversing relay and a power relay, each of said reversing and power relays including contacts in circuit connection with said main winding, and means for controlling actuation of said relays.

14. A drive system for a rotary file of the type including a housing having an access opening, a plurality of card carrying receptacles, means mounting said receptacles for movement within the housing relative to the access opening, said drive system comprising an alternating current, induction motor having a main winding, an excitation phase brake winding, and a short circuit brake winding, a control circuit for controlling the direction of operation of said motor and the dynamic braking thereof, said control circuit comprising a brake relay having contacts in circuit with said excitation phase winding, a reversing relay and a power relay, each of said reversing and power relays including contacts in circuit connection with said main winding and means for controlling actuation of said relays, said last named means comprising a first switch for completing a circuit to said reversing relay, power relay and braking relay, and a second switch for completing a circuit to said power relay and braking relay and means for maintaining said braking relay closed for a short period after said power relay is opened.

15. A drive system for a rotary file of the type including a housing having an access opening, a plurality of card carrying receptacles, means mounting said receptacles for movement within the housing relative to the access opening, said drive system comprising an alternating current, induction motor having a main winding, an excitation phase brake winding, and a short circuit brake winding, a control circuit for controlling the direction of operation of said motor and the dynamic braking thereof, said control circuit comprising a brake relay having contacts in circuit with said excitation phase winding, a reversing relay and a power relay, each of said reversing and power relays including contacts in circuit connection with said main winding, and means for controlling actuation of said relays, said last named means comprising a plurality of selectively operable switches, a rotary selector switch having stationary contacts respectively connected to each of said switches, a rotary disc member having two conductive portions insulated from one another, two commutator contacts in respective electrical connection with each of said conductive portions, one of said commutator contacts being connected to said reversing relay and being connected to said braking and power relays through a norm-ally open contact of said braking relay, the other of said commutator contacts being connected to said brake relay and power relay through a normally closed contact of said brake relay.

References Cited in the file of this patent UNITED STATES PATENT 5 2,928,706 Abbott et al Mar. 15, 1960 

